Solid electrolyte, electrochemical device including the same and method of fabricating the solid electrolyte

ABSTRACT

A solid electrolyte with excellent ionic conductivity, which is composed of a viscoelastic material having a structure of a polymerized material and a non-aqueous electrolytic solution contained in the polymerized material, a chemical element containing the solid electrolyte, and a method of fabricating the solid electrolyte are described. This solid electrolyte contains the non-aqueous electrolytic solution in an amount of 200 wt. % or more of the polymer and has a modulus of elasticity of 10 2  to 10 5  dyne/cm 2 , and an elongation of 20% or more.

FIELD OF THE INVENTION

This invention relates to a novel solid electrolyte, an electrochemicaldevice including the solid electrolyte, and a method of producing thesolid electrolyte.

BACKGROUND OF THE INVENTION

In the field of electrochemical devices including a an electrolyte, itis strongly desired that the electrolyte be solidified. Conventionally,an electrolytic solution is employed in batteries serving aselectrochemical devices. Therefore, not only the leakage of theelectrolytic solution, and the drying of the electrolytic solutionwithin the battery due to the evaporation of the electrolytic solutionoccur, but also the partial drying of the separator due to theimbalanced presence of the electrolytic solution in the battery cellcauses an increase in the internal impedance or an internal shortcircuit in the battery. Furthermore, in the field of solid electrolytesfor use in a display element for electrochromic devices, a solidelectrolyte which sufficiently satisfies the requirement for theoperational speed has never been obtained. As countermeasures forsolving these problems, the use of polymeric solid electrolytes has beenproposed. Specific examples of such polymer electrolytes are solidsolutions of matrix polymers containing oxyethylene chains oroxypropylene chains, and inorganic salts. These are complete solids andhave excellent machining properties. However, the ionic conductivitiesthereof are 10⁻⁵ S/cm at room temperature, which are about 3 orders lessthan those of ordinary non-aqueous electrolytic solutions. As a methodof improving the low ionic conductivity, the use of a polymer solidelectrolyte film with a thickness in the order of microns has beenproposed. However, it is difficult to control the thickness of themicron-order thick polymer solid electrolyte film in such a manner thatthe electric field in the battery cell is kept constant. The reliabilityof the battery cell obtained is therefore low.

In order to improved the ionic conductivity of a polymer solidelectrolyte, a method of making a polymer solid electrolyte semi-solidby dissolving the same in an organic electrolytic solution (JapaneseLaid-Open Patent Application 54-104541) and a method of polymerizing aliquid monomer with the addition of an electrolyte to produce across-linked polymer including the electrolyte (Japanese Laid-OpenPatent Application 63-94501) have been proposed. However, the formermethod has the problem that the obtained solid electrolyte does not havesufficient solid strength, and the latter method has the problem thatthe ionic conductivity of the obtained cross-linked polymer includingthe electrolyte is not satisfactory.

The present invention solves the above-mentioned problems of theconventional polymer-based solid electrolytes, and provides apolymer-based solid electrolyte which not only has excellent ionicconductivity, but also excellent uniformity, and has a sufficient solidstrength for use as a solid electrolyte for electrochemical devices, anda method of fabricating the solid electrolyte having such particularproperties.

DISCLOSURE OF THE INVENTION

This invention provides the following:

(1) A solid electrolyte characterized in that it is a viscoelasticmaterial composed of a non-aqueous electrolytic solution and apolymerized material, and the content of the non-aqueous electrolyticsolution is 200 wt. % or more of the polymerized material.

(2) A solid electrolyte characterized in that it is a viscoelasticmaterial composed of a non-aqueous electrolytic solution and apolymerized material, the content of the nonaqueous electrolyticsolution is 200 wt. % or more of the polymerized material, and themodulus of elasticity of the viscoelastic material is 10² to 10⁵dyne/cm² and the elongation is 20% or more.

(3) A solid electrolyte characterized in that it is a viscoelasticmaterial composed of a non-aqueous electrolytic solution which comprisesan electrolytic salt and a nonaqueous solvent, and a polymer of anacrylate having a molecular weight of less than 500, represented by thefollowing formula (I) or a polymer of an unsaturated carboxylic acidester comprising as the main component the acrylate, the content of thenon-aqueous electrolytic solution is 200 wt. % or more of the polymer,and the content of the electrolytic salt in the non-aqueous electrolyticsolution is 1.0 mol/l or more: ##STR1## wherein R₁ represents a hydrogenatom, or a methyl group, R₂ represents a hydrocarbon group or a groupcontaining a heterocyclic ring, and n is an integer of 1 or more.

(4) A solid electrolyte characterized in that it is a viscoelasticmaterial composed of a non-aqueous electrolytic solution which comprisesan electrolytic salt and a nonaqueous solvent, and a polymer of acompound represented by the following formula (II) or a polymer of anunsaturated carboxylic acid ester comprising as the main component thecompound, the content of the non-aqueous electrolytic solution is 200wt. % or more of the polymer, and the content of the electrolyte salt inthe non-aqueous electrolytic solution is 1.0 mol/l or more: ##STR2##wherein R₃ represents a hydrogen atom, or a methyl group, and R₄represents a group containing a heterocyclic ring.

(5) An electrochemical device including any of the above solidelectrolytes.

6) A method of fabricating a solid electrolyte characterized by thesteps of dissolving 100 parts by weight of any of the above-mentionedcompounds with formula (I) or the formula (II) or an unsaturatedcarboxylic acid ester comprising as the main component any of the abovecompounds in 200 parts by weight or more of a non-aqueous electrolyticsolution with the concentration of the electrolyte being 1.0 mole/l ormore, in the presence of a polymerization initiator, to polymerize theabove to produce a viscoelastic polymer.

The solid electrolyte of the present invention is composed of aviscoelastic material comprising a polymer and a non-aqueouselectrolytic solution, which is uniform in its entirety.

The viscoelastic solid electrolyte of the present invention has theproperties of high ionic conductivity, low elasticity, low glasstransition temperature (Tg), high stability to high temperatures, easymachining, low creep characteristics, and adhesiveness, and has bothexcellent liquid holding performance and shape-retention propertiesalthough it contains a large amount of an electrolytic solution. Thesolid electrolyte of the present invention normally has an ionicconductivity of 10⁻⁴ to 10⁻² S/cm at 25° C. when measured by an A.C.impedance method. This conductivity is largely effected by theconductivity of the non-aqueous electrolytic solution which is onecomponent of the solid electrolyte, but does not exceed the above valueand is scarcely decreased by the solidification of the electrolyte. Theelasticity of the solid electrolyte of the present invention, measuredby a dynamic viscoelasticity testing machine (Trademark "RDS-7700" madeby Rheometric Inc.), is normally 10⁶ dyne/cm² or less, preferably 10² to10⁵ dyne/cm², and more preferably 10³ to 10⁵ dyne/cm². The glasstransition temperature of the solid electrolyte of the present inventionis -30° C. or less, and the elongation thereof is 20% or more. The solidelectrolyte has a recovery power to a maximum of about 400% drawdeformation without breaking. Furthermore, it does not break when folded180 degrees.

The measurement of the deformation with time of the solid electrolyte ofthe present invention by use of a creep meter (Trademark "RR-3305"commercially available from Sanden Co., Ltd.) with a plunger crosssection area of 2 cm² and a load of 30 g indicated that the solidelectrolyte has low creep characteristics with no deformation againsttime. Even if the solid electrolyte of the present invention is pressedby the creep meter with application of a load of 25 g/cm² thereto, theelectrolytic solution contained therein does not leak out. Furthermore,this viscoelastic material exhibits high adhesiveness, so that whenthese viscoelastic materials are applied to each other, neither bepeeled away from the applied surface without being broken.

The solid electrolyte of the present invention can be formed bysubjecting polymerizable materials to a polymerization reaction in anon-aqueous electrolytic solution. The polymerizable materials used hereexhibit not only thermal polymerizability, but also polymerizability bylight and active light rays such as ultraviolet rays, electron rays,gamma rays, and X-rays.

The polymerizable materials for use in the present invention contain intheir molecules hetero atoms other than carbon atoms, such as oxygen,nitrogen and sulfur atoms. In the solid electrolytes (viscoelasticmaterials) obtained by dissolving the polymerizable materials containingthese hetero atoms in a non-aqueous electrolytic solution andpolymerizing the same, the hetero atoms other than carbon atoms are alsoconsidered to have the functions of promoting the ionization of theelectrolytic salt employed, improving the ionic conductivity of thesolid electrolyte, and increasing the strength of the solid electrolyte.

There is no particular restriction in the choice of the kinds of thepolymerizable materials used in the present invention. Materials whichcan be polymerized by thermal polymerization and active light rays canalso be used, but materials which exhibit photopolymerization byapplication of active light rays are preferable. Examples of thermalpolymerization include an urethane-bond forming reaction andpolymerizations in which an epoxy group or an acrylate group isinvolved. Of these reactions, the urethane-bond forming reaction ispreferable. Examples of the photo-polymerization reactions byapplication of active light rays include polymerization usingunsaturated carboxylic acid esters, polyene/polythiol mixtures andcross-linking macromers such as organic silanes andpolyisothianaphthene. Of these, the polymerization reactions usingunsaturated carboxylic acid esters or polyene/polythiol mixtures arepreferable in the present invention.

The polymerization reaction of unsaturated carboxylic acid esters, thepolymerization reaction of the mixtures of polyene/polythiol, and thepolyurethane-forming reaction, which are excellent as the polymerizationreactions in an electrolytic solution, will now be explained in detail.

In the present specification, the term "(meth)acrylate" means acrylateor methacrylate, and the term "(meth)acryloyle group" means acryloylegroup or methacryloyle group.

As the polymerization reaction in a non-aqueous electrolytic solution inorder to obtain the solid electrolyte of the present invention,photopolymerization by use of active light rays, which is alow-temperature process, is preferable in order to avoid the thermaldecomposition of the solid electrolyte to be obtained. Examples of thephotopolymerizable materials with application of active light raysinclude (meth)acrylate, and a combination of polyene and polythiol.Examples of the (meth)acrylate include monofunctional and polyfunctional(meth)acrylates. Examples of the monofunctional acrylates are alkyl(meth)acrylates such as methyl (meth)acrylate, butyl (meth)acrylate, andtrifluoroethyl (meth)acrylate; alicyclic (meth)acrylates such astetrahydrofurufuryl (meth)acrylate; hydroxyalkyl (meth)acrylates such ashydroxyethyl acrylate and hydroxypropyl acrylate; hydroxypolyoxyalkylene(meth)acrylates (preferably the oxylenealkyl group having 1 to 4 carbonatoms) such as hydroxypolyoxyethylene (meth)acrylate andhydroxypolyoxypropylene (meth)acrylate; and alkoxy (meth)acrylates(preferably the alkoxy group having 1 to 4 carbon atoms) such asmethoxyethyl acrylate, ethoxyethyl acrylate, and phenoxyethyl acrylate.Preferable examples of the polyfunctional (meth)acrylates are, of thephotopolymerizable monomers and photo-polymerizable prepolymersdescribed on pages 142-152 of "UV, EB Curing Technology" published bySogo Gijutsu Center Co., Ltd., the three or more functional monomers andprepolymers such as trimethylolpropane tri(meth)acrylate,pentaerythritol (meth)acrylate, and dipentaerythritolhexa(meth)acrylate.

Of the above acrylates, the acrylates represented by the followingformula (I), having a molecular weight of less than 500, and theacrylates represented by the following formula (II) are particularlypreferable: ##STR3## wherein R₁ represents a hydrogen atom, or a methylgroup, R₂ represents a hydrocarbon group or a group containing aheterocyclic ring, and n is an integer of 1 or more. ##STR4## wherein R₃represents a hydrogen atom, or a methyl group, and R₄ represents a groupcontaining a heterocyclic ring.

In the above formula (I), R₂ represents a hydrocarbon group or a groupcontaining a heterocyclic ring. Examples of the hydrocarbon groupinclude aliphatic groups and aromatic groups. Examples of the aliphatichydrocarbon groups are those having 1 to 10 carbon atoms, such asmethyl, ethyl, propyl, butyl, hexyl and octyl groups, preferablyaliphatic hydrocarbon groups having 1 to 5 carbon atoms. Examples of thearomatic hydrocarbon groups are phenyl, tolyl, xylyl, naphthyl, benzyl,and phenethyl groups. Examples of the group containing a heterocyclicring include a variety of heterocyclic rings including hetero atoms suchas oxygen, nitrogen, and sulfur. Examples of such groups includefurfuryl group and tetrahydrofurfuryl group. Specific examples of theacrylate represented by formula (I) include alkylethylene glycolacrylates such as methylethylene glycol acrylate, ethylethylene glycolacrylate, propylethylene glycol acrylate, and phenylethylene glycolacrylate; alkylpropylene glycol acrylates such as ethylpropylene glycolacrylate and butylpropylene glycol acrylate; alkylene glycol acrylatesincluding a heterocyclic ring such as furfurylethylene glycol acrylate,tetrahydrofurfurylethylene glycol acrylate, furfurylpropylene glycolacrylate, and tetrahydrofurfurylpropylene glycol acrylate.

The acrylates represented by formula (I) have a molecular weight of lessthan 500, but those having a molecular weight of 300 or less arepreferable. In the case of acrylates having a molecular weight of 500 ormore, the non-aqueous solvent easily oozes out of the solid electrolyteobtained therefrom.

There is no particular restriction in the choice of the heterocyclicring contained in the meth)acrylates represented by formula (II).Examples of the groups containing such a heterocyclic ring are theresidues of heterocyclic rings containing hetero atoms such as oxygen,nitrogen or sulfur. Examples of the (meth)acrylates represented byformula (II) include furfuryl (meth)acrylate, and tetrahydrofurfuryl(meth)acrylate. Of these, furfuryl acrylate and tetrahydrofurfurylacrylate are preferable for use.

The compounds represented by formula (I) or formula (II) can be usedalone or by combining two or more of those compounds.

By use of the compound represented by formula (I) or formula (II) incombination with a polyfunctional unsaturated carboxylic acid ester, asolid electrolyte which ideally has both excellent elasticity and ionicconductivity can be obtained. Examples of such a polyfunctionalunsaturated carboxylic acid ester are those having two more(meth)acryloyl groups. Preferable examples of the polyfunctional thepolyfunctional unsaturated carboxylic acid ester are, of thephoto-polymerizable monomers and photo-polymerizable prepolymersdescribed on pages 142-152 of "UV, EB Curing Technology" published bySogo Gijutsu Center Co., Ltd., the two or more functional monomers andprepolymers such as diethylene diglycol di(meth)acrylate, butanedioldi(meth)acrylate, trimethylolpropane tri(meth)acrylate, anddipentaerythritol hexa(meth)acrylate. Of these, three-functional(meth)acrylates are most preferable in view of the fact that theyprovide solid electrolytes which have excellent liquid retainingperformance, ionic conductivity and strength.

The usable amount of the compounds represented by formula (I) or formula(II), or of the unsaturated carboxylic acid ester comprising as the maincomponent any of the above compounds is 50 wt. % or less, preferably inthe range of 5 to 40 wt. %, more preferably in the range of 10 to 30 wt.%, with respect to the amount of the non-aqueous electrolytic solution.When the amount is more than 50 wt. %, the ionic conductivity andstrength of the solid electrolyte are decreased.

In the case where the compound of formula (I) or formula (II) is used incombination with the polyfunctional unsaturated carboxylic acid esterthe amount of the polyfunctional unsaturated carboxylic acid ester is 4wt. % or less, preferably in the range of 0.05 to 2 wt. % with respectto the non-aqueous electrolytic solution. In particular, when athree-functional unsaturated carboxylic acid ester is employed incombination with the compound of formula (I) or formula (II), a solidelectrolyte with excellent ionic conductivity and strength can beobtained by use of as small an amount of the three-functionalunsaturated carboxylic acid ester as 2 wt. % or less, more preferably inthe range of 0.05 to 0.5 wt. % with respect to the nonaqueouselectrolytic solution. Thus, by the combined use of such polyfunctionalunsaturated carboxylic acid esters, solid electrolytes with better ionicconductivity and strength can be obtained. However when too much of thepolyfunctional unsaturated carboxylic acid esters is used incombination, the solid electrolytes obtained do not exhibitviscoelasticity, and lack flexibility, and cracks tend to be easilyformed upon application of an external force thereto.

Examples of polymerization initiators for polymerizing the compoundsrepresented by formula (I) or formula (II), and the unsaturatedcarboxylic acid esters comprising as the main component any of the abovecompounds include: carbonyl compounds, for example, benzoin compoundssuch as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoinpropyl ether, benzoin isobutyl ether, α-methyl benzoin, and α-phenylbenzoin; anthraquinone compounds such as anthraquinone,methylanthraquinone, chloroanthraquinone; other compounds such asbenzil, diacetyl, acetophenone, benzophenone, and methylbenzoylfomate;sulfides such as diphenylsulfide and dithiocarbamate; halides ofpolycondensation cyclic hydrocarbons such as α-chloromethyl naphthalene;dyes such as acryl fravin, and fluorecein; metal salts such as ironchloride and silver chloride; and onium salts such as p-methoxybenzenediazonium, hexafluorophosphate, and diphenyliodonium. Thesepolymerization initiators can be used alone or in the form of a mixtureof two or more. Photopolymerization initiators preferable for use in thepresent invention are the carbonyl compounds, the sulfides and the oniumsalts. When necessary, thermal polymerization initiators such asazobisisobutyronitrile, benzoyl peroxide, lauroyl peroxide, and ethylmethyl ketone peroxide can be used in combination with the abovepolymerization initiators. Furthermore, polymerization initiators suchas dimethylaniline, cobalt naphthenate, sulfinic acid, and mercaputancan also be employed in combination with the above polymerizationinitiators. Furthermore, sensitizers and preservation stabilizing agentscan also be employed in combination with the above polymerizationinitiators when necessary. Specific examples of the sensitizers are, ofthe sensitizers described on pages 158 to 1569 of "UV, EB CuringTechnology" published by Sogo Gijutsu Center Co., Ltd., urea, nitrilecompounds such as N,N-disubstituted-p-aminobenznitrile; and phosphoruscompounds such as tri-n-butylphosphine. Specific examples of thepreservation stabilizing agents are, of the preservation stabilizingagents described on pages 158 to 1569 of "UV, EB Curing Technology"published by Sogo Gijutsu Center Co., Ltd., tertiary ammonium chloride,benzothiazole, and hydroquinone.

The amount of the polymerization initiators employed is normally in therange of 0.1 to 10 wt. %, preferably in the range of 0.5 to 7 wt. %,with respect to the amount of the entire unsaturated carboxylic acidesters employed. When the amount of the polymerization initiatorsexceeds the above normal range, an appropriate reactivity cannot beobtained. The amounts of each of the sensitizer and the preservationstabilizing agent are normally in the range of 0.1 to 5 parts by weightto 100 parts by weight of the entire unsaturated carboxylic acid estersemployed.

The solidification of the electrolytic solution in the present inventioncan be performed by injecting into a sealed container the non-aqueouselectrolytic solution containing the previously mentioned compound offormula (I) or formula (II) or the unsaturated carboxylic acid estercomprising as the main component the above compound of formula (I) orformula (II), or by coating the non-aqueous electrolytic solution on asupport, for instance, made of a film, metal or glass, followed bypolymerizing the nonaqueous electrolytic solution with application ofheat or active light rays. As the active light rays, normally light,ultraviolet rays, electron rays and X-rays can be employed. Of theseactive light rays, those having a main wavelength in the range of 100 to800 nm are preferable for use in the present invention. The solidifiedelectrolytic solution, that is, the solid electrolyte, can be workedinto a product in the form of a film or a sheet, or in a composite formin combination with a part of an electrochemical device.

As the electrolytic solution, either an aqueous electrolytic solution ora non-aqueous electrolytic solution can be used, but a non-aqueouselectrolytic solution is preferable for use in the present invention.The solid electrolyte of the present invention exhibits excellentperformance, when used in a battery containing a non-aqueouselectrolytic solution such as a lithium battery, in the place of thenon-aqueous electrolytic solution. As an example of a non-aqueouselectrolytic solution to be solidified, one in which an electrolyticsalt is dissolved in a non-aqueous electrolytic solution can be given.There is no particular restriction in the choice of the electrolyticsalt so long as ordinary non-aqueous electrolytic solutions areemployed. Specific examples of the electrolytic salt include LiClO₄,LiBF₄, LiAsF₆, LiPF₆, LiCF₃ SO₃, LiCF₃ COO, NaClO₄, NaBF₄, NaSCN, KBF₄,Mg(ClO₄)₂, Mg(BF₄)₂. When used in batteries, electrolytic salts havinglow molecular weights are preferable.

Examples of the non-aqueous solvent include propylene carbonate,γ-butyrolactone, ethylene carbonate, sulfolane, dioxolane,tetrahydrofuran, 2-methyl tetrahydrofuran, dimethyl sulfoxide,1,2-dimethoxyethane, 1,2-ethoxyethane, and glimes such as methyldiglime, methyl triglime, methyl tetraglime, ethyl glime, ethyl diglime,and butyl diglime. Of these, the combinations of the glimes, andpropylene carbonate, and/or γ-butyrolactone are preferable in view ofthe ionic conductivity and the solubility of the electrolytic salts.

The concentration of the electrolytic salt in a nonaqueous electrolyticsolution is normally in the range of 1.0 to 7.0 moles/l, and preferablyin the range of 2.0 to 5.0 moles/l. When the concentration is less than1.0 mole/l, a solid electrolyte having sufficient strength cannot beobtained. When the concentration of the electrolytic salt exceeds 7.0moles/l dissolving the electrolytic salt becomes difficult. The amountof the non-aqueous electrolytic solution is normally 200 wt. % or more,preferably in the range of 400 to 900 wt. %, more preferably in therange of 500 to 800 wt. % of a polymer which constitutes a matrix. Whenthe amount of the non-aqueous electrolytic solution is less than 200 wt.%, a sufficiently high ionic conductivity cannot be obtained, while whenthe amount exceeds 900 wt. %, the solidification of the non-aqueouselectrolytic solution becomes difficult.

In order to obtain the solid electrolyte of the present invention, it isnecessary to adjust the concentrations of the electrolytic salt and theunsaturated carboxylic acid ester in the non-aqueous electrolyticsolution to appropriate concentrations. Thus, there is a closerelationship between the concentration of the electrolytic salt and thatof the unsaturated carboxylic acid ester. When the concentration of theelectrolytic salt is close to 1.0 mole/l which is the minimumconcentration, the concentration of the entire unsaturated carboxylicacid esters must be in the range of about 20-50 wt. % to produce a solidelectrolyte having satisfactory characteristics, while when theconcentration of the electrolytic salt is as high as 3 moles/l or more,the concentration of the entire unsaturated carboxylic acid esters maybe in the range of about 10-20 wt. % in order to obtain a satisfactorysolid electrolyte.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG.1 is a diagram showing the preferable composition ranges of asolvent, an electrolytic salt and an unsaturated carboxylic acid esterwhich constitute the solid electrolyte of the present invention.

FIG.2 is a voltammogram of a polyaniline obtained in Example 1 of thepresent invention.

FIG.3 shows the charging-discharge curves of a battery obtained inExample 5 of the present invention.

SPECIFIC EXPLANATION OF THE INVENTION

FIG.1 shows the composition ranges of a solvent, an electrolytic saltand an unsaturated carboxylic acid ester which constitute a solidelectrolyte obtained by using an unsaturated carboxylic acid ester whichcontains a compound represented by general formula (I). In FIG.1, thearea enclosed with A, B, C, D, E and A shows a preferable compositionarea, the area enclosed with K, L, M, I, J, and K shows a morepreferable area, and the area enclosed with R, M, I, J, and R shows aparticularly preferable area, in which a solid electrolyte which is mostsuitable in both elasticity and ionic conductivity.

The compositions of the unsaturated carboxylic acid ester, theelectrolytic salt and the solvent at each point in FIG.1 are as follows:

A: (0, 100, 0)

B: (33, 67, 0)

C: (33, 0, 67)

D: (30, 0, 70)

E: (0, 30, 70)

F: (10, 52, 38)

G: (33, 38, 29)

H: (33, 5, 62)

I: (24, 6, 70)

J: (10, 20, 70)

K: (10, 32, 58)

L: (24, 28, 48)

M: (28, 5, 67)

P: (10, 28, 62)

Q: (27, 11, 62)

R: (10, 23, 67)

The polymerization reaction of a mixture of polyene and polythiolfundamentally proceeds in accordance with the following formulas:##STR5## wherein R and R' each represent an organic group such as analkyl group.

Examples of the polyene are polyallyl ether compounds and polyallylester compounds. Examples of the polyallyl ether compounds are compoundsprepared by addition of an epoxy compound such as ethylene oxide,propylene oxide, butylene oxide, styrene oxide, cyclohexene oxide,epihalohydrin, allyl glycidyl ether to a saturated or unsaturated allylalcohol. Of these compounds, those obtained by addition of ethyleneoxide or propylene oxide to a saturated or unsaturated ally alcohol arepreferable.

Examples of the polyallyl ester compounds are reaction products of allylalcohol or the above-mentioned polyallyl ether compounds and acarboxylic acid. Examples of the carboxylic acid include aliphatic,alicyclic and aromatic mono- and poly-carboxylic acids, for example,monocarboxylic acids such as acetic acid, propionic acid, butyric acid,octanoic acid, lauric acid, stearic acid, oleic acid and benzoic acid(with 1 to 20 carbon atoms); and dicarboxylic acids such as adipic acidand phthalic acid. Of these compounds, the reaction products of thepolyallyl ether compounds and polycarboxylic acids are preferable.

Examples of polythiol include a liquid polysulfide; aliphatic, alicyclicand aromatic polythiol compounds; and mercaptocarboxylic acid esters. Asan example of the liquid polysufide, Thiokol LP Series (Toray ThiokolCo., Ltd.) can be given. Of these polythiols, those having an averagemolecular weight of 400 or less are preferable. Examples of thealiphatic, alicyclic and aromatic polythiol compounds include methane(di)thiol, and ethane (di)thiol. Examples of the mercaptocarboxylic acidesters include compounds obtained by the esterification reaction of amercaptocarboxylic acid and a polyhydric alcohol or by the esterexchange reaction of a mercaptocarboxylic acid alkyl ester and apolyhydric alcohol. As examples of the mercaptocarboxylic acid,2-mercaptoacetic acid and 3-mercaptopropionic acid can be given. Asexamples of the polyhydric alcohol, ethylene glycol, trimethylolpropane, glycerol, pentaerythritol, sucrose, and alkylene oxide adductsof these compounds such as ethylene oxide adducts, propylene oxideadducts, and butylene oxide adducts. Preferable polyhydric alcohols arethose having 3 or more hydroxyl groups, which do not contain alkyleneoxide adducts. Examples of the mercaptocarboxylic acid alkyl esterinclude 2-mercaptoethyl acetate, and 3-mercaptomethyl propionate.Preferable polythiols are the liquid polysufide and mercaptocarboxylicacid esters.

As the polymerization initiators for the reaction mixture of the polyeneand polythiol, the same polymerization initiators as employed for thepolymerization of the unsaturated carboxylic acid esters can be used.

Examples of compounds which are thermal polymerizable include acombination of a polyisocyanate which forms polyurethane, a polyoland/or a cross-linking agent, and prepolymers prepared by the samecombination. As the polyol, those described on pages 99-117 of "Handbookof Polyurethane Resins" (published by Nikkan Kogyo Shinbun Co., Ltd.)can be given. Of the polyols described therein, polyoxyalkylene polyolshaving a melting point of 10° C. or less which are formed bypolymerizing alkylene oxides such as ethylene oxide, propylene oxide andtetrahydrofuran are preferable. In this case, there may be one or morealkylene groups in the polyoxyalkylene polyols. Of the abovepolyoxyalkylene polyols, a polyoxyalkylene polyol prepared bycopolymerizing ethylene oxide and propylene oxide is particularlypreferable. The polyoxyalkylene polyol may be a mixture of two or morepolyoxyalkylene polyols. The melting point of the polyoxyalkylenepolyols is normally 10° C. or less, preferably in the range of 0° C. to-60° C. When the melting point exceeds 10° C., the ionic conductivity ofthe solid electrolyte decreases because of the crystallizing properties.The hydroxyl number of the polyoxyalkylene polyol is normally 84 orless, and preferably 60 or less. When the hydroxyl number exceeds 84,the ionic conductivity of the solid electrolyte decreases. Preferablepolyisocyanates are tolylene diisocyante, 4,4'-metaphenylenediisocyanate, isophorone diisocyanate, and prepolymers of thesediisocyanates, out of the polyisocyanates described on pages 90 to 98 ofthe previously cited reference. The content ratio of the NCO group isnormally 48 wt. % or less, preferably 40 wt. % or less. When the NCOgroup content ratio exceeds 48 wt. %, the ionic conductivity of thesolid electrolyte decreases. As the cross-linking agent, polyhydricalcohols and polyfunctinal amines as well as water, out of thecross-linking agents described on pages 122-123 of the previously citedreference, can be employed. Of these cross-linking agents, polyhydricalcohols such as ethylene glycol are preferable. The polyol and/or thecross-linking agent and the polyisocyanate provide a polyurethane bypolyaddition reaction, when necessary in the presence of a catalyst. Inthis case, catalysts which are conventionally used in the synthesis ofpolyurethane can be given as such a catalyst. Specific examples of suchcatalysts are triethylene diamine and stannous octoate.

As an electrolytic solution employed for forming a solid electrolyteusing a reaction of the polyene/polythiol mixture and a urethane-formingreaction, the same electrolytic solutions as employed when a solidelectrolyte is formed by the polymerization reaction of the unsaturatedcarboxylic acid esters can be given.

It is preferable that a dipping auxiliary, which decreases the surfacetension of a non-aqueous electrolytic solution and improves thepenetration of the non-aqueous electrolytic solution into a separatorfilm or active materials be added to a non-aqueous electrolytic solutionwhich is employed to obtain the solid electrolyte of the presentinvention. Examples of such a dipping auxiliary are silicone derivativessuch as silicone oil and siliconealkylene oxide adducts; polypropyleneoxide derivatives; perfluoroalkylsulfonic acid salts; fluorinederivatives such as perfluoroalkyl quaternary ammonium iodides,perfluoroalkyl polyoxyethylene ethanol, and fluorinated alkyl esters.The amount of such a dipping auxiliary employed is normally in the rangeof 0.1 to 10 wt. % and preferably in the range of 0.5 to 5 wt. % in thesolid electrolyte. When the amount of the dipping auxiliary exceed therange of 0.1 to 10 wt. %, an economical dipping effect cannot beobtained.

The solid electrolyte of the present invention is preferably fabricatedin an atmosphere of inert gas. In this case, a solid electrolyte withbetter ionic conductivity and strength can be obtained in comparisonwith a solid electrolyte produced in air.

The solid electrolyte of the present invention can be used as a layer ofsolid electrolyte in electrochemical devices such as batteries,condensers, electrochromic devices and semi-conductor devices. The casewhere the solid electrolye of the present invention is used as anelectrolyte for batteries will now be explained.

Generally, a battery is composed of a positive electrode comprising anactive material, a negative electrode comprising an active material, aseparator, and an electrolyte. An unconventally excellent battery can beobtained when the solid electrolyte of the present invention is used asthe elecrolyte in such a battery. When the solid electrolyte of thepresent invention is employed in the battery, it is also possible toassign the function of a separator to the solid electrolyte so that thesolid electrolye works as the electrolyte and a separator as well. Inorder to make uniform the electric field between the anode and thecathode, thereby improving the reliability of the battery obtained, itis preferable to integrate the electrolyte and the separator. Inparticular, such a configuration is necessary in the case of a secondarybattery. In the present invention, the integration of the separtor andthe solid electrolyte is easily accomplished by directly forming thesolid electrolyte in a battery cell having a separator, or bypenetrating a solid- electrolyte-forming composition into the separatorand polymerizing the same. In this case, it is preferable that a dippingauxiliary be added to the solid-electrolyte- forming composition.

Examples of active materials for the positive electrode in the batteryinclude chalcogenite compounds such as TiS₂, Nb₃ S₄, MoS₂, CoS₂, FeS₂,V₂ O₅, Cr₂ O₅, MnO₂ and CoO₂ ; and electro-active polymers, for example,electroconductive polymers such as polyaniline, polypyrrole,poly-3-methyl-thiophene, polydiphenylbenzidine, and polyazulene, andmetalocene polymer. Of these anode-electric active materials, theelectro-active polymers are preferable, and the electroconductivepolymers are more preferable.

Examples of cathode-active materials include metals such as Li, Na, K,Ag, Cu and Zn; alloys such as alloys of Li with Al, Mg, Pb, Si, Mn, Gaor In; electroconductive polymers such as polyacetylene, polythiophene,polyparaphenylene, polypyridine, polyacene, graphite andelectrochemically active carbons. Of these cathode-active materials,lithium, lithium alloys, and electroconductive polymers are preferable.When an electroconductive polymer is employed in the active materialsfor the positive and/or negative electrode, it is necessary to dissolvean electrolytic salt in the electrolytic solution in an amount greaterthan the doping amount thereof, therefore a solid electrolyte in whichthe concentration of the electrolytic salt is high and the content ofthe electrolytic solution is large is obtained.

In the present invention, a separator which exhibits low resistance tothe movement of ions and has excellent liquid-holding properties isemployed. Examples of such a separator are a glass fiber filter;polymer-based pore filters and non-woven fabrics made of a polymer suchas polyester, teflon, polyethylene, or polypropylene; a paper-like sheetmade from glass fiber and polymer fiber. A composite material comprisinga non-woven fabric made of polypropylene with micro pores with adiameter of 0.1 to 0.01 μm and a solid electrolyte is particularlyadvantageous over other separators in terms of performance.

A battery of the present invention can be produced by using aviscoelastic material comprising a polymer and a non-aqueous electricsolution in place of a solid electrolyte employed in conventionalbatteries. The solid electrolyte of the present invention can be formedby polymerizing a polymerizable material, which is dissolved in anon-aqueous electric solution, and converting the reaction liquid into aviscoelastic material with high flexibility. Therefore it is preferablethat the formation be carried out by direct polymerization on anelectrode or on a separator, or within an electric cell. Morespecifically, it is preferable that battery elements such as electrodesand a separator be impregnated with a solid electrolyte formationcomposition, and the solid electrolyte formation composition be made aviscoelastic material by polymerization means such as heating orapplication of active light rays thereto, so that the formed solidelectrolyte and the battery elements are integrated. Each batteryelement and the solid electrolyte may be integrated with respect to eachbattery element, but such integration can be applied to the combinationof a positive electrode and a separator, the combination of a negativeelectrode and a separator, and the combination of a positive electrode,a negative electrode and a separator. When the battery elements and thesolid electrolyte are integrated in this manner, the reaction at thepositive and negative electrodes and the ion transfer can be caused toproceed smoothly, so that the inner resistance of the battery can besignificantly reduced.

The solid electrolyte of the present invention exhibits preferablecharacteristics when it is used in a composite form with anelectroconductive polymer. This is because a monomer solution penetratesa polymer before the polymerization of the monomer solution to swell thepolymer, and then sufficiently penetrates the polymer, and thereafterthe monomer solution is solidified by polymerization, so that nospecific interfaces are formed between the the solid electrolyte and thepolymer, resulting in a reduction of the interface resistance betweenthe two. In the case of conventional solid electrolytes, represented bya solid electrolyte of the type comprising a polymer matrix and aninorganic salt, containing dissociated ionic groups, polarization easilytakes place in the interface between the solid electrolyte and an activematerial, so that there is a large interface resistance between them. Incontrast to this, the solid electrolyte of the present invention hasliquid-like properties but is in the form of a solid as mentionedpreviously. Therefore, positive ions and negative ions move easilywithin the solid electrolyte in the same manner as in conventionalelectrolyte solutions, so that little of the above-mentionedpolarization takes place in a battery in which an electroconductivepolymer is used. Therefore it can be said that the combination of thesolid electrolyte of the present invention and the electroconductivepolymer is a preferable one.

The composition of an electroconductive polymer and the solidelectrolyte of the present invention is generally carried out byimpregnating the electroconductive polymer with a solid electrolyteformation composition, followed by converting the composition to aviscoelastic material by means of polymerization as mentionedpreviously.

In the present invention, for example, the following can be used as theelectroconductive polymer: polymers of heterocyclic five-membered ringcompounds prepared from a monomer such as pyrrole or thiophene; polymersof aromatic hydrocarbon compounds prepared from a monomer such asbenzene or azulene; polymers of amine compounds prepared from a monomersuch as aniline and diphenylbenzene; polyarylene-vinylene which isuseful as the covering material of a negative electrode; and unsaturatedaliphatic polymers prepared from monomers such as halogen-substitutedcompounds of unsaturated hydrocarbons such as ethylene, butadiene, andhexatriene. These monomers can be polymerized by chemical polymerizationby using oxidizing agents or by electrochemical polymerization by usingelectric energy.

The chemical polymerization can be carried out by adding an oxidizingagent to a solution containing a monomer and oxidizing the monomer.Examples of the oxidizing agent are halogens such as iodine, bromine,and iodobromide; metal halogenides such as arsenic pentafluoride,antimony pentafluoride, silicon fluoride, and phosphorus pentachloride;protonic acids such as sulfuric acid, nitric acid, fluorosulfuric acid,and chlorosulfuric acid; oxygen-containing compounds such as sulfurtrioxide, nitrogen dioxide, potassium dichromate, potassium permaganate;persulfates such as sodium persulfate, potassium persulfate, andammonium persulfate; and peroxides such as hydrogen peroxide, peraceticacid, and difluorosulfonyl peroxide. Polymers with a high degree ofpolymerization obtained by chemical polymerization are insoluble insolvents and obtained in the form of a powder. In the case of apowder-like active material, regardless of whether it is an inorganicmaterial or an organic material, the methods of composing an activematerial and an electrolytic solution can be roughly classified into twomethods. The first method is to solidify an electrolytic solution in anactive material which serves as a framework material. The second methodis to form a composite material of an active material and anelectrolytic solution and solidify the composite material. In the casewhere the first method is applied to a powder-like electroconductivepolymer synthesized by chemical polymerization, the powder-likeelectroconductive polymer is formed into a desired shape for theelectrode, such as a pellet- or sheet-shape, and the appropriatelyshaped polymer is impregnated with a solid electrolyte formingcomposition, followed by composing the electroconductive polymer and thesolid electrolyte by means of polymerization with the application ofheat or active light rays thereto. When the second method is applied, anappropriate amount of the solid electrolyte formation composition isadded to the powder-like electroconductive polymer, the polymer issufficiently impregnated with the solid electrolyte formationcomposition, the two components are mixed to prepare a paste-likemixture, and the paste-like mixture is formed into the desired shape andcomposed by means of polymerization with the application of heat oractive light rays thereto. Either in the first method or in the secondmethod, when necessary, other additives, for example, anelectroconductive material such as acetylene black, ketjen black, andgraphite, can be added to the above components. In the presentinvention, since the solid electrolyte serves as a binder agent as well,it is unnecessary to use a binder agent such as teflon.

In the case where an electrode is prepared by use of the above-mentionedpaste-like mixture, any shape can be made. However, when the electrodeis in the shape of a pellet, the paste-like mixture is formed into apellet, or firmly applied to a porous carbon member or a foamed metalmember to work it into a pellet. When preparing a sheet-shapedelectrode, the paste-like mixture is firmly applied to or coated on asheet-shaped material such as a blast-treated punching metal, a metalmesh, an expand metal and a carbon fiber fabric.

Syntheses of electroconductive polymers by electrochemicalpolymerization are described, for instance, in J. Electrochem. Soc.,Vol.130. No. 7. 1506-1509(1983), Electrochem. Acta., Vol.27. No.61-85(1982), J.Chem.Soc., Chem.Commun., 1199- (1984). Thispolymerization can be carried out by placing a solution of a monomer andan electrolyte dissolved in a solvent in an appropriate electrolyticchamber, immersing the electrodes, and subjecting the reaction mixtureto anode-oxidation or cathode-oxidation. Examples of such an electrolyteare electrolytes with anions such as BF₄ ⁻, AsF₆ ⁻, SbF₆ ⁻, PF₆ ⁻, ClO₄⁻, HSO₄ ⁻, SO₄ ²⁻, and aromatic sulfonic acid anions, and cations suchas hydrogen ion, quaternary ammonium cation, lithium, sodium andpotassium cations, although the electrolytes are not particularlylimited to these electrolytes. Examples of the solvent are water,acetonitrile, benzonitrile, propylene carbonate, γ-butyrolactone,dichloromethane, dioxane, dimethylformamide, and nitro compound solventssuch as nitromethane, nitroethane, nitropropane, and nitrobenzene,although the solvents are not particularly limited to these solvents.For the electrochemical polymerization, constant-voltage electrochemicalpolymerization, constant-current electrochemical polymerization andconstant-potential electrochemical polymerization are possible. In theelectrochemical polymerization, a sheet-shaped electrode can be formedsubstantially in one stage by using a sheet-shaped electroconductivemember as a reaction electrode. Therefore, the electrochemicalpolymerization is essentially suitable for the fabrication of asheet-shaped electrode. In composing a polymer prepared by theelectrochemical polymerization and the solid electrolyte of the presentinvention, when the electroconductive polymer is utilized by recoveringthe same in the form of powder, the previously mentioned first andsecond methods are employed. However, when an electrode, on which anelectroconductive polymer obtained by the electrochemical polymerizationis deposited, is used as is, the composition is possible by sufficientlyimpregnating the electroconductive polymer on the electrode with a solidelectrolyte forming composition and then by conducting thepolymerization.

In order to improve the energy capacity of an electrode comprising suchan electroconductive polymer, it is also possible to compose theelectrode with the addition of an inorganic active material. Examples ofsuch an active material include chalcogenite compounds such as TiS₂, Nb₃S₄, MoS₂, CoS₂, FeS₂, V₂ O₅, Cr₂ O₅, MnO₂, CoO₂ and WO₃. For composingsuch powder-like chalcognite compounds, any of the compounds is added toa composition system of the previously mentioned powder-likeelectroconductive polymer and the solid electrolyte, or the powder-likeelectroconductive polymer is dispersed in the above system at the timeof electrochemical polymerization, and incorporated into theelectroconductive polymer. The methods of composing the active materialconsisting essentially of the electroconductive polymer and the solidelectrolyte, and the method of fabricating the electrode with thecomposite solid electrolyte. The composition of an alkali metal whichserves as an active material for the negative electrode, in particular,lithium or a lithium alloy, and the solid electrolyte, the compositionof a powder-like (or particle-shaped) active material such as Li-Al,Li-Mg, Li-Pb, Li-Al-Mg or Li-Al-Mn and the solid electrolyte and thefabrication of an electrode with a composite solid electrolyte can becarried out by the same procedure as in the composition of thepowder-like electroconductive polymer and the solid electrolyte. Thecomposition of the solid electrolyte and a sheet-shaped metal activematerial can be performed by uniformly coating a solid electrolyteforming composition on the surface of the sheet-shaped metal activematerial and forming a solid electrolyte on the surface thereof by meansof polymerization with application of heat or active light rays. Suchcompositions are of course important for the reduction of the interfaceresistance, but by securely forming the solid electrolyte on theinterface of a metal active material for a negative electrode, such asLi or a Li-Al-based alloy, for the composition, the formation of amoss-shaped lithium or a dendrite can be prevented, and the destructionof the Li-Al-based alloys can be suppressed. This leads to theimprovement of the charge-discharge efficiency of the negativeelectrode, and the extension of battery cycle life. Thus, thiscomposition is extremely important. From the view point of theimprovement of the charge-discharge efficiency of the negativeelectrode, it is possible to solidify an electrolytic solution to besolidified, with the addition of various additives which contribute tothe improvement of the charge-discharge efficiency. Examples of suchadditives are organic materials such as benzene, crown ethers including12-crown-4, 15-crown 5; and hetero-atom-containing 5-membered ringcompounds, 2-methyfuran, 2,5-dimethylfuran, 2-methylthiophene,2,5-dimethylthiophene, and 4-methylthiazole. Inorganic additives canalso be employed. Examples of such inorganic additives are compositionscomprising metal ions such as Mg(II) and Fe(III). Specific examples areMg(Cl₄)₂, MgCl₂, Fe(ClO₄)₂, and FeCl₃. Generally the addition amount ofsuch additives is approximately in the order of ppm to 1 mol/l, althoughthe most effect amount varies depending upon the kind of the additive.

According to the present invention, a battery can be fabricated byintegrally composing a positive electrode, a negative electrode, a solidelectrolyte with a separator interposed therebetween to form a layeredtype battery, or by winding the integral composite in a spiral shape toform a coin type battery, a cylindrical battery, a square battery, athin plate type battery, and a sheet-shaped battery, suitable for eachbattery cartridge.

The present invention will now be explained in more detail withreference to the following examples. The present invention is notlimited to these examples. Hereinafter, the terms "part(s)" and "%"respectively mean "parts by weight" and "wt. %".

The solid electrolyte forming compositions employed in the examples andcomparative examples were as follows. Each non-aqueous solvent and eachelectrolytic salt were sufficiently purified, with the content of waterreduced to 20 ppm or less, followed by the elimination of oxygen andnitrogen therefrom, with the purity grades thereof being set for use inbatteries. Experiments were all conducted in an atmosphere of argon. Themeasurement of ionic conductivity was conducted at 25° C.

The measurement of the ionic conductivity of each solid electrolyte wasconducted by two methods. Specifically, in the first method, themeasurement was conducted by filling a solid electrolyte in acylindrical container made of SUS with an inner diameter of 20 mm, whichconstitutes a counter electrode, and placing a cylinder made of SUS witha diameter of 5 mm, with the outer peripheral surfaces thereof beingconnected through teflon, which serves as a work electrode, in pressurecontact with the surface of the solid electrolyte. The values of theionic conductivity obtained by this method are shown with a mark (*). Inthe second method, the measurement was conducted by filling a solidelectrolyte in a cylindrical container made of SUS with an innerdiameter of 20 mm, with the inner peripheral surface except the innerbottom surface thereof being covered with an insulating tape, whichconstitutes a counter electrode, and placing a cylinder made of SUS witha diameter of 18 mm, which serves as a work electrode, in pressurecontact with the surface of the solid electrolyte. The values of theionic conductivity obtained by this method are shown with a mark (**).

Solid electrolyte forming composition (I)

In a non-aqueous solvent consisting of a mixture of propylene carbonateand 1,2-dimethoxy ethane with a weight ratio of 6:4, LiBF₄ is dissolvedwith a ratio of 3 moles/l to prepare an electrolytic solution. Thissolid electrolyte forming composition is a mixture of 79.2% of the aboveelectrolytic solution, 19.5% of ethoxydiethylene glycol acrylate, 0.8%of methyl benzoylformate, and 0.5% of a silicone-alkylene oxide adduct.

Solid electrolyte forming composition (II)

In a non-aqueous solvent consisting of a mixture of propylene carbonate,γ-butyrolactone, and 1,2-dimethoxy ethane with a weight ratio of 7:1:2,LiBF₄ is dissolved with a ratio of 3 moles/l to prepare an electrolyticsolution. This solid electrolyte forming composition is a mixture of68.8% of the above electrolytic solution, 29% of ethoxydiethylene glycolacrylate, 1.2% of benzoine isopropyl ether, and 1.0% of asilicone-alkylene oxide adduct.

Solid electrolyte forming composition (III)

In a non-aqueous solvent consisting of a mixture of propylene carbonate,and 1,2-dimethoxy ethane with a weight ratio of 7:3, LiBF₄ is dissolvedwith a ratio of 3 moles/l to prepare an electrolytic solution. Thissolid electrolyte forming composition is a mixture of 85.8% of the aboveelectrolytic solution, 12.8% of ethoxydiethylene glycol acrylate, 0.2%of trimethylolpropane triacrylate, 0.5 methylbenzoylformate, and 0.7% ofa silicone-alkylene oxide adduct.

Solid electrolyte forming composition (IV)

In a non-aqueous solvent consisting of a mixture of propylene carbonate,and 1,2-dimethoxy ethane with a weight ratio of 6:4, LiBF₄ is dissolvedwith a ratio of 3 moles/l to prepare an electrolytic solution. Thissolid electrolyte forming composition is a mixture of 79.2% of the aboveelectrolytic solution, 19.5% of furfuryl acrylate, 0.8% ofmethylbenzoylformate, and 0.5% of a silicone-alkylene oxide adduct.

Solid electrolyte forming composition (V)

In a non-aqueous solvent consisting of a mixture of propylene carbonate,-butyrolactone, and 1,2-diethoxy ethane with a weight ratio of 7:1:2,LiBF₄ is dissolved with a ratio of 3 moles/l to prepare an electrolyticsolution. This solid electrolyte forming composition is a mixture of68.8% of the above electrolytic solution, 30% of tetrahydrofurfurylacrylate, and 1.2% of benzoine isopropyl ether.

EXAMPLE 1

0.5 moles of aniline was dissolved in 1000 parts of a 5.5N aqueoussolution of H₂ SO₄. By use of this solution, a polyaniline thin film wasformed on a Nesa glass (1 cm×2 cm) with a surface resistance of 4Ω/□with a constant potential of 0.8 V vs SCE and a charge quantity of 0.02C/cm². The thus obtained polyaniline thin film was subjected to apredetermined reduction treatment to convert the same to a completelyreduced polyaniline thin film. The polyaniline thin film wassufficiently dried to prepare a polyaniline electrode. By use of lithiumfor a counter electrode and for a reference electrode, together with theabove electrode, a beaker type cell was fabricated. The solidelectrolyte forming composition (II) was placed in this cell andirradiated with active light rays by use of a fluorescent lamp for 8hours. The composition was completely solidified in a viscoelastic form,without fluidity, and was integrated with the electrode with remarkableadhesion. With the polyaniline electrode being used as a workingelectrode, the cyclic voltammetry was measured with a potential sweeprate of 25 mV/sec. As a result, a voltammogram as shown in FIG. 2 wasobtained. From the voltammogram, it was confirmed that the solidelectrolyte exhibits the same excellent doping characteristics as in anelectrolytic solution. The ionic conductivity of the solid electrolytewas 1.5×10⁻³ S/cm*, and 1.0×10⁻³ S/cm**.

EXAMPLE 2

0.5 moles of aniline was dissolved in 1000 parts of a 5.5N aqueoussolution of H By use of this solution, a polyaniline thin film wasformed on a Nesa glass (1 cm×2 cm) with a surface resistance of 4Ω/□with a constant potential of 0.8 V vs SCE and a charge quantity of 0.04C/cm². The thus obtained polyaniline thin film was subjected to apredetermined reduction treatment to convert the same to a completelyreduced polyaniline thin film. The polyaniline thin film wassufficiently dried to prepare a polyaniline electrode. By use of lithiumfor a counter electrode and for a reference electrode, together with theabove electrode, a beaker-shaped cell was fabricated. The solidelectrolyte forming composition (III) was placed in this cell andirradiated with active light rays by use of a high pressure mercury arclamp for 1.5 hours. The composition was completely solidified in aviscoelastic form, without fluidity, and was integrated with theelectrode with remarkable adhesion. With the polyaniline electrode beingused as a work electrode, the doping amount of the polyanine wasmeasured. The results were 118 mAh/g at 25° C., 108 mAh/g at 0° C., and103 mAh/g at -20° C., so that it was confirmed that excellent dopingcharacteristics can be obtained in a relatively low temperature range.The ionic conductivity of the solid electrolyte was 4×10⁻³ S/cm*, and2.7×10⁻³ S/cm**.

EXAMPLE 3

Polyaniline was synthesized in accordance with the method described inA.G. MacDiarmid et al., Conducting Polymers., 105 1987) using ammoniumpersulfate and hydrochloric acid. The synthesized polyaniline wassufficiently subjected to a reduction treatment, so that whitepowder-like polyaniline was obtained. 75 parts of the white powder-likepolyaniline and 25 parts of acetylene black were kneaded. By pressureforming, the kneaded mixture was formed into a disc-shaped positiveelectrode with a diameter of 14.5 mm and a thickness of 0.6 mm. Thispositive electrode was sufficiently impregnated with the solidelectrolyte forming composition (I), held between a pair of glasssubstrates and irradiated by active light rays by a high pressuremercury arc lamp, so that the solid electrolyte forming composition wassolidified. A separator (Trademark "Juragurd 2502" made by PolyscienceCo., Ltd.) was also sufficiently impregnated with the composition (I) inthe same manner as mentioned above, held between a pair of glasssubstrates and irradiated by active light rays by a high pressuremercury acr lamp, so that the composition was solidified. As a negativeelectrode, a 0.1 mm thick lithium was employed. The above-mentionedpositive electrode, the separator and the negative electrode wereoverlaid, whereby a coin type battery (CR2016 type) was fabricated.

EXAMPLE 4

A polyaniline film with a thickness of 0.1 mm was deposited on one sideof a 0.02 mm thick, surface-roughened punching metal made of SUS by aconstant-current electrochemical polymerization using an aqueoussolution containing 1 mol/l of aniline and 3 mol/l of HBF₄, with aconstant current of 3 mA/cm². The thus obtained polyaniline film wassubjected to a reduction treatment and sufficiently dried in vacuum. Thefilm was then applied to an external material of aPET/aluminum/polypropylene layered composite film. The polyaniline filmwas sufficiently impregnated with the solid electrolyte formingcomposition (I), held between a pair of glass substrates with theapplication of a pressure of 1 kg, and irradiated with active light raysby a high pressure mercury arc lamp, whereby a sheet-shaped positiveelectrode composed of a composite film of the positive electrode and asolid electrolyte was obtained. A separator ("Tonen Tapyrus P010SW-000)was placed on this sheet-shaped positive electrode, sufficientlyimpregnated with the solid electrolyte forming composition (I), heldbetween a pair of glass substrates, and irradiated with active lightrays by a high pressure mercury arc lamp to solidify the composition.Apart from the above, a negative electrode prepared by applying a 0.1 mmthick lithium to a 0.02 mm SUS substrate was applied to an externalmaterial of a PET/aluminum/polypropylene layered composite film. Thesolid electrolyte forming composition (I) was coated on the lithium,held between a pair of glass substrates, and irradiated with activelight rays by a high pressure mercury arc lamp to solidify thecomposition, whereby the negative electrode and the solid electrolytewere composed. The above-mentioned positive electrode, the separator,and the negative electrode were overlaid to prepare a layered compositefilm. The peripheral portion of the layered composite film was heatsealed, whereby a sheet-shaped battery with a size of 4 cm×5 cm wasfabricated.

EXAMPLE 5

A polyaniline film was deposited in an amount of 5 mg/cm² on one side ofa 0.02 mm thick, surface-roughened punching metal made of SUS by aconstant-current electrochemical polymerization using an aqueoussolution containing 1 mol/l of aniline and 3 mol/l of HBF₄, with aconstant current of 3 mA/cm². The thus obtained polyaniline film wassubjected to a reduction treatment and sufficiently dried in vacuum. Thefilm was then applied to an external material of aPET/aluminum/polypropylene layered composite film. The polyaniline filmwas sufficiently impregnated with the solid electrolyte formingcomposition (III), held between a pair of glass substrates with theapplication of a pressure of 1 kg, and irradiated with active light raysby a high pressure mercury arc lamp, whereby a sheet-shaped positiveelectrode composed of a composite film of the positive electrode and asolid electrolyte was obtained. A separator ("Cell Guard 4501") wasplaced on this sheet-shaped positive electrode, sufficiently impregnatedwith the solid electrolyte forming composition (III), and irradiatedwith active light rays to solidify the composition. Apart from theabove, a negative electrode prepared by applying a 0.08 mm thick lithiumto a 0.02 mm SUS substrate was applied to an external material of aPET/aluminum/polypropylene layered composite film. The solid electrolyteforming composition (III) was coated on the lithium, held between a pairof glass substrates, and irradiated with active light rays by a highpressure mercury arc lamp to solidify the composition, whereby thenegative electrode and the solid electrolyte were composed. Theabove-mentioned positive electrode, the separator, and the negativeelectrode were overlaid to prepare a layered composite. The peripheralportion of the layered composite film was heat sealed, whereby asheet-shaped battery with a size of 5 cm×7 cm was fabricated. Thisbattery was charged up to 3.7 V with a constant current of 2.2 mA andthen discharged with different currents. FIG. 3 shows thecharge-discharge curves in this case.

EXAMPLE 6

A 0.3 mm thick aluminum was superimposed on a 0.1 mm thick lithium. Thiscomposite film was then heated, so that a lithium/aluminum alloy layeredcomposite film was prepared. This was used as a negative electrode. Thelithium/aluminum alloy surface of this negative electrode wasimpregnated with the solid electrolyte forming composition (I) and thecomposition was solidified. The procedure for Example 3 was repeatedexcept that the negative electrode employed in Example 3 was replaced bythe above prepared negative electrode, whereby a coin type battery(CR2016 type) was fabricated.

Performance Tests for the Batteries

The performance of each of the batteries fabricated in Examples 3, 4 and6 was evaluated by conducting charging and discharging of each batterywith a constant current of 0.5 mA. The results are shown in TABLE 1.

                  TABLE 1                                                         ______________________________________                                                  Open-      Discharge Discharge                                                circuit    Capacity  Capacity                                       Examples  Voltage    (initial) (after 30 cycles)                              ______________________________________                                        Example 3 3.7 V      7.5 mAh   7.0 mAh                                        Example 4 3.7 V      12.5 mAh  11.0 mAh                                       Example 6 3.2 V      7.1 mAh   6.5 mAh                                        ______________________________________                                    

EXAMPLE 7

The formulation of the previously mentioned solid electrolyte formingcomposition (I) was modified in such a manner that the content of theelectrolytic solution was changed to 69.1%, the content of theethoxydiethylene glycol acrylate was changed to 29.6%, and theconcentration of the electrolytic salt was changed to prepare a solidelectrolyte forming composition (I') similar to the composition (I) wasused. The composition (I') was placed in a beaker and irradiated withactive light rays from a fluorescent lamp for 8 hours, and theproperties of the obtained polymerization reaction product wereinvestigated. The results are shown in TABLE 2.

                  TABLE 2                                                         ______________________________________                                        Concen-                                                                       tration of                                                                    Electrolytic  Properties of Polymerization Products                           Samples                                                                              Salt       Ionic Conductivity                                          No.    (moles/l)  S/cm*      S/cm**  Form                                     ______________________________________                                        1      0.5        --         --      Liquid                                   2      1          5 × 10.sup.-3                                                                      3.3 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 3      1.5        5 × 10.sup.-3                                                                      3.3 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 4      2          4 × 10.sup.-3                                                                      2.7 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 5      5          2 × 10.sup.-3                                                                      1.3 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 6      7          1.5 × 10.sup.-3                                                                    1.0 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 7      10         1.0 × 10.sup.-3                                                                    0.7 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 ______________________________________                                    

EXAMPLE 8

The formulation of the previously mentioned solid electrolyte formingcomposition (II) was modified with the concentration of the electrolyticsalt was changed to prepare a variety of solid electrolyte formingcompositions. Each of the compositions was placed in a beaker andirradiated with active light rays from a fluorescent lamp for 8 hours,and the properties of the obtained polymerization reaction products wereinvestigated. The results are shown in TABLE 3.

                  TABLE 3                                                         ______________________________________                                        Concen-                                                                       tration of                                                                    Electrolytic  Properties of Polymerization Products                           Samples                                                                              Salt       Ionic Conductivity                                          No.    (moles/l)  S/cm*      S/cm**  Form                                     ______________________________________                                        1      0.5        --         --      Liquid                                   2      1.0        3 × 10.sup.-3                                                                      2.0 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 3      2.0        2 × 10.sup.-3                                                                      1.3 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 4      3.0        1.5 × 10.sup.-3                                                                    1.0 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 5      4.0        1.0 × 10.sup.-3                                                                    0.8 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 6      5.0        1.0 × 10.sup.-3                                                                    0.7 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 ______________________________________                                    

EXAMPLE 9

0.5 moles of aniline was dissolved in 1000 parts of a 5.5N aqueoussolution of H₂ SO₄. By use of this solution, a polyaniline thin film wasformed on a Nesa glass (1 cm×2 cm) with a surface resistance of 4Ω/□with a constant potential of 0.8 V vs SCE and a charge quantity of 0.02C/cm². The thus obtained polyaniline thin film was subjected to apredetermined reduction treatment to convert the same to a completelyreduced polyaniline thin film. The polyaniline thin film wassufficiently dried to prepare a polyaniline electrode. By use of lithiumfor a counter electrode and for a reference electrode, together with theabove electrode, a beaker type cell was fabricated. The solidelectrolyte forming composition (V) was placed in this cell andirradiated with active light ray by use of a fluorescent lamp for 8hours. The composition was completely solidified in a viscoelastic form,without fluidity, and was integrated with the electrode with remarkableadhesion. With the polyaniline electrode being used as a workingelectrode, the cyclic voltammetry was measured at potential sweep ratesof 50 mV/sec and 20 mV/sec. From the voltammogram, it was confirmed thatthe solid electrolyte exhibits the same excellent doping characteristicsas in the electrolytic solution. The ionic conductivity of the solidelectrolyte was 1.7×10⁻³ S/cm*, and 1.2×10⁻³ S/cm**.

EXAMPLE 10

Polyaniline was synthesized in accordance with the method described inA. G. MacDiarmid et al., Conducting Polymers., 105 (1987) using ammoniumpersulfate and hydrochloric acid. The synthesized polyaniline wassufficiently subjected to a reduction treatment, so that whitepowder-like polyaniline was obtained. 75 parts of the white powder-likepolyaniline and 25 parts of acetylene black were kneaded. By pressureforming, the kneaded mixture was formed into a disc-shaped positiveelectrode with a diameter of 14.5 mm and a thickness of 0.6 mm. Thispositive electrode was sufficiently impregnated with the solidelectrolyte forming composition [IV), held between a pair of glasssubstrates and irradiated by active light rays by a high pressuremercury arc lamp, so that the solid electrolyte forming composition wassolidified. A separator (Trademark "Juragurd 2502" made by PolyscienceCo., Ltd.) was also sufficiently impregnated with the composition (I) inthe same manner as mentioned above, held between a pair of glasssubstrates and irradiated by active light rays by a high pressuremercury acr lamp, so that the composition was solidified. As a negativeelectrode, a 0.1 mm thick lithium was employed. The above-mentionedpositive electrode, the separator and the negative electrode wereoverlaid, whereby a coin type battery (CR2016 type) was fabricated.

EXAMPLE 11

A polyaniline film with a thickness of 0.1 mm was deposited on one sideof a 0.02 mm thick, surface-roughened punched metal sheet made of SUS bya constant-current electrochemical polymerization using an aqueoussolution containing 1 mol/l of aniline and 3 mol/l of HBF₄, with aconstant current of 3 mA/cm². The thus obtained polyaniline film wassubjected to a reduction treatment and sufficiently dried in vacuum. Thefilm was then applied to an external material of aPET/aluminum/polypropylene layered composite. The polyaniline film wassufficiently impregnated with the solid electrolyte forming composition(IV), held between a pair of glass substrates with the application of apressure of 1 kg, and irradiated with active light rays by a highpressure mercury arc lamp, whereby a sheet-shaped positive electrodecomposed of a composite film of the positive electrode and a solidelectrolyte was obtained. A separator ("Tonen Tapyrus P010SW-000") wasplaced on this sheet-shaped positive electrode, sufficiently impregnatedwith the solid electrolyte forming composition (IV), held between a pairof glass substrates, and irradiated with active light rays by a highpressure mercury arc lamp to solidify the composition. Apart from theabove, a negative electrode prepared by applying a 0.1 mm thick lithiumto a 0.02 mm SUS substrate was applied to an external material of aPET/aluminum/polypropylene layered composite. The solid electrolyteforming composition (IV) was coated on the lithium, held between a pairof glass substrates, and irradiated with active light rays by a highpressure mercury arc lamp to solidify the composition, whereby thenegative electrode and the solid electrolyte were composed. Theabove-mentioned positive electrode, the separator, and the negativeelectrode were overlaid to prepare a layered composite. The peripheralportion of the layered composite film was heat sealed, whereby asheet-shaped battery with a size of 4 cm×5 cm was fabricated.

EXAMPLE 12

A 0.3 mm thick aluminum was superimposed on a 0.1 mm thick lithium. Thiscomposite film was then heated, so that a lithium/aluminum alloy layeredcomposite film was prepared. This was used as a negative electrode. Thelithium/aluminum alloy surface of this negative electrode wasimpregnated with the solid electrolyte forming composition (IV) and thecomposition was solidified. The procedure for Example 2 was repeatedexcept that the negative electrode employed in Example 2 was replaced bythe above prepared negative electrode, whereby a coin type battery(CR2016 type) was fabricated.

Performance Tests for the Batteries

The performance of each of the batteries fabricated in Examples 10 to 12was evaluated by conducting charging and discharging of each batterywith a constant current of 0.5 mA. The results are shown in TABLE 4.

                  TABLE 4                                                         ______________________________________                                                  Open-      Discharge Discharge                                                circuit    Capacity  Capacity                                       Examples  Voltage    (initial) (after 30 cycles)                              ______________________________________                                        Example 10                                                                              3.7 V      7.4 mAh   7.0 mAh                                        Example 11                                                                              3.7 V      12.3 mAh  10.9 mAh                                       Example 12                                                                              3.2 V      7.2 mAh   6.7 mAh                                        ______________________________________                                    

EXAMPLE 13

The formulation of the previously mentioned solid electrolyte formingcomposition (IV) was modified in such a manner that the content of theelectrolytic solution was changed to 69.1%, and the content of thefurfuryl acrylate was changed to 29.6% to prepare a solid electrolyteforming composition (IV') similar to the composition (IV) was used. Thecomposition (IV') was placed in a beaker and irradiated with activelight rays from a fluorescent lamp for 8 hours, and the properties ofthe obtained polymerization reaction product were investigated. Theresults are shown in TABLE 5.

                  TABLE 5                                                         ______________________________________                                        Concen-                                                                       tration of                                                                    Electrolytic  Properties of Polymerization Products                           Samples                                                                              Salt       Ionic Conductivity                                          No.    (moles/l)  S/cm*      S/cm**  Form                                     ______________________________________                                        1      0.5        --         --      Liquid                                   2      1            5 × 10.sup.-3                                                                    3.4 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 3      1.5        4.7 × 10.sup.-3                                                                    3.1 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 4      2          4.2 × 10.sup.-3                                                                    2.8 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 5      5          2.3 × 10.sup.-3                                                                    1.5 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 6      7          1.4 × 10.sup.-3                                                                    1.0 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 7      10         1.1 × 10.sup.-3                                                                    0.7 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 ______________________________________                                    

EXAMPLE 14

The formulation of the previously mentioned solid electrolyte formingcomposition (V) was modified with the concentration of the electrolyticsalt was changed to prepare a variety of solid electrolyte formingcompositions. Each of the compositions was placed in a beaker andirradiated with active light rays from a fluorescent lamp for 8 hours,and the properties of the obtained polymerization reaction products wereinvestigated. The results are shown in TABLE 6.

                  TABLE 6                                                         ______________________________________                                        Concen-                                                                       tration of                                                                    Electrolytic  Properties of Polymerization Products                           Samples                                                                              Salt       Ionic Conductivity                                          No.    (moles/l)  S/cm*      S/cm**  Form                                     ______________________________________                                        1      0.5        --         --      Liquid                                   2      1.0        2.8 × 10.sup.-3                                                                    2.0 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 3      2.0        1.7 × 10.sup.-3                                                                    1.3 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 4      3.0        1.7 × 10.sup.-3                                                                    1.2 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 5      4.0        1.2 × 10.sup.-3                                                                    1.0 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 6      5.0        1.0 × 10.sup.-3                                                                    0.7 × 10.sup.-3                                                                 Viscoelastic                                                                  Solid                                                                         Material                                 ______________________________________                                    

EXAMPLE 15

In 1000 parts of a non-aqueous solvent consisting of propylene carbonateand γ-butyrolactone with a weight ratio of 8:2, one mole of LiBF₄ wasdissolved to prepare an electrolytic solution. 89.1% of thiselectrolytic solution, 6.5% of a polyene (a reaction product by allowing400 parts of a polyoxyethylene glycol with a molecular weight of 400 toreact with 342 parts of allylglycidyl ether), 3.6% of pentaerythritoltetrakisthioglycolate, 0.4% of methylbenzoylformate, and 0.5% of asilicone-alkylene oxide adduct were mixed, whereby a solid electrolyteformation composition (VI) was obtained.

An electrolytic manganese dioxide (EMD) having a β layer, acetyleneblack ("Denka Black"), and PTFE Dispersion (PJ-30 made by Mitsui FloroChemical Co., Ltd.) were kneaded in a weight ratio of 7.5:2.0:0.5. Bypressure forming, the kneaded mixture was formed into a disc with adiameter of 14.5 mm and a thickness of 0.6 mm. The thus formed disc wassufficiently dried with application of heat, impregnated with the abovesolid electrolyte formation composition (VI), held between a pair ofglass substrates, and irradiated with active light rays to solidify thecomposition, whereby a positive electrode was obtained. By use of thispositive electrode, and the separator and the negative electrodeemployed in Example 2, a coin type battery (CR2016 type) was fabricated.

EXAMPLE 16

The formulation of the previously mentioned solid electrolyte formingcomposition (VI) was modified with the concentration of the electrolyticsalt was changed to prepare a variety of solid electrolyte formingcompositions. Each of the compositions was placed in a beaker andirradiated with active light rays from a fluorescent lamp for 8 hours,and the properties of the obtained polymerization reaction products wereinvestigated. The results are shown in TABLE 7.

                  TABLE 7                                                         ______________________________________                                                         Properties of                                                Concentration of Polymerization Products                                      Samples                                                                              Electrolytic Salt                                                                           Ionic Conductivity                                       No.    (moles/l)     (S/cm*)       Form                                       ______________________________________                                        1      0.5           --            Liquid                                     2      1.0           5.5 × 10.sup.-3                                                                       Viscoelastic                                                                  Solid                                                                         Material                                   3      2.0           5 × 10.sup.-3                                                                         Viscoelastic                                                                  Solid                                                                         Material                                   4      3.0           4 × 10.sup.-3                                                                         Viscoelastic                                                                  Solid                                                                         Material                                   5      4.0           3 × 10.sup.-3                                                                         Viscoelastic                                                                  Solid                                                                         Material                                   6      5.0           2 × 10.sup.-3                                                                         Viscoelastic                                                                  Solid                                                                         Material                                   ______________________________________                                    

EXAMPLE 17

A solid electrolyte forming composition with the following formulationwas prepared:

    ______________________________________                                        Toluene diisocyanate    2.4 parts                                             Polyoxyalkylene polyol  27.6 parts                                            Electrolytic solution   70 parts                                              Catalyst (dibutyl tin laurate)                                                                        0.1 parts                                             ______________________________________                                    

As the above-mentioned polyoxyalkylene polyol, a polyol with a molecularweight of 3000 (m.p. 0° C. or less), prepared by addition polymerizationof ethylene oxide/propylene oxide (=8/2 by weight ratio) to glycerin,was employed.

As the above-mentioned electrolytic solution, a solution of 3 moles/l ofLiBF₄ dissolved in γ-butyrolactone was employed.

The above composition was placed in a beaker and heated to 50° C. for 1hour, so that a polymerization reaction product was obtained and theproperties thereof were investigated. The results are shown in TABLE 8.

                  TABLE 8                                                         ______________________________________                                                         Properties of                                                Concentration of Polymerization Products                                      Samples                                                                              Electrolytic Salt                                                                           Ionic Conductivity                                       No.    (moles/l)     (S/cm*)       Form                                       ______________________________________                                        1      0.5           8 × 10.sup.-2                                                                         Liquid                                     2      1             7.5 × 10.sup.-3                                                                       Viscoelastic                                                                  Solid                                                                         Material                                   3      2             7 × 10.sup.-3                                                                         Viscoelastic                                                                  Solid                                                                         Material                                   4      3             6 × 10.sup.-3                                                                         Viscoelastic                                                                  Solid                                                                         Material                                   5      4             5 × 10.sup.-3                                                                         Viscoelastic                                                                  Solid                                                                         Material                                   6      5             5 × 10.sup.-3                                                                         Viscoelastic                                                                  Solid                                                                         Material                                   ______________________________________                                    

EXAMPLE 18

In 1000 parts of a non-aqueous solvent consisting of propylene carbonateand 1,2-dimethoxy ethane with a weight ratio of 6:4, three moles ofLiBF₄ were dissolved to prepare an electrolytic solution. 79.2% of thiselectrolytic solution, 19.5% of hydroxyethyl acrylate, 0.8% ofmethylbenzoylformate, and 0.5% of a silicone-alkylene oxide adduct weremixed, whereby a solid electrolyte formation composition (VII) wasobtained.

The formulation of the above-mentioned solid electrolyte formingcomposition (VII) was modified with the concentration of theelectrolytic salt was changed to prepare a variety of solid electrolyteforming compositions. Each of the compositions was placed in a beakerand irradiated with active light rays from a fluorescent lamp for 8hours, and the properties of the obtained polymerization reactionproducts were investigated. The results are shown in TABLE 9.

                  TABLE 9                                                         ______________________________________                                                         Properties of                                                Concentration of Polymerization Products                                      Samples                                                                              Electrolytic Salt                                                                           Ionic Conductivity                                       No.    (moles/l)     (S/cm*)       Form                                       ______________________________________                                        1      0.5           --            Liquid                                     2      1.0           4.0 × 10.sup.-3                                                                       Viscoelastic                                                                  Solid                                                                         Material                                   3      2.0           3.5 × 10.sup.-3                                                                       Viscoelastic                                                                  Solid                                                                         Material                                   4      3.0             2 × 10.sup.-3                                                                       Viscoelastic                                                                  Solid                                                                         Material                                   5      4.0           1.5 × 10.sup.-3                                                                       Viscoelastic                                                                  Solid                                                                         Material                                   6      5.0           1.0 × 10.sup.-3                                                                       Viscoelastic                                                                  Solid                                                                         Material                                   ______________________________________                                    

EXAMPLE 19

One part of trimethylol propane triacrylate was mixed with 64 parts ofethoxydiethylene glycol acrylate to prepare an unsaturated carboxylicacid ester mixture A. A non-aqueous solvent B was prepared by mixingpropylene carbonate and 1,2-dimethoxyethane with a weight ratio of 8:2.The mixture A, the non-aqueous solvent B and LiBF₄ (electrolytic salt)were mixed to prepare the compositions with the following formulations.Each of the compositions was placed in a beaker and irradiated withactive light rays by a high pressure mercury arc lamp for 1 hour. Themodulus of elasticity and the elongation of each of the thus obtainedpolymerization reaction products were measured. The results are shown inTABLE 10. Methylbenzoyl formate was used as the polymerizationinitiator. The measurement of the elongation of the solid electrolyteswas conducted for solid electrolytes with a size of 1 cm×1 cm×0.3 cm.

                  TABLE 10                                                        ______________________________________                                        Composition of   Properties of                                                Reaction Liquid  Solid Electrolyte                                                  Electro- Non-      Modulus       Ionic                                  Mix-  lytic    aqueous   of      Elong-                                                                              Conduc-                                ture A                                                                              Salt     Solvent B Elasticity                                                                            ation tivity                                 part(s))                                                                            (part(s))                                                                              (part(s)) (dyne/cm.sup.2)                                                                       (%)   (S/cm*)                                ______________________________________                                        1.3   2.0      6.7       2.5 × 10.sup.3                                                                  95      4 × 10.sup.3                   2.0   1.8      6.2       1.5 × 10.sup.4                                                                  60    3.5 × 10.sup.3                   2.5   1.0      6.5       8 × 10.sup.3                                                                    50      4 × 10.sup.3                   1.2   2.6      6.2       3 × 10.sup.3                                                                    120     3 × 10.sup.3                   1.2   1.9      6.9       6 × 10.sup.2                                                                    150     4 × 10.sup.3                   1.2   1.3      7.5       --      --    --                                     2.4   0.6      7.0       1 × 10.sup.3                                                                    45      8 × 10.sup.3                   2.0   1.2      6.8       1 × 10.sup.4                                                                    70      4 × 10.sup.3                   2.0   2.2      5.8       5 × 10.sup.4                                                                    35    1.5 × 10.sup.3                   2.0   3.0      5.0       9 × 10.sup.4                                                                    30    0.9 × 10.sup.3                   2.5   3.0      4.5       1 × 10.sup.5                                                                    20    0.6 × 10.sup.3                    3.5* 2.5      4.0       7 × 10.sup.5                                                                    15    0.1 × 10.sup.3                   ______________________________________                                         *shows Comparative Example.                                              

COMPARATIVE EXAMPLE 1

100 parts of a polyethylene oxide triol with a molecular weight of 3000,0.06 parts of dibutyl tin dilaurate, 8.5 parts oftoluene-2,4-diisocyanate, and 5.4 parts of LiBF₄ were dissolved in 100parts of methyl ethyl ketone, whereby a composition (a) was obtained.

The procedure for Example 10 was repeated except that the solidelectrolyte forming composition (I) employed in Example 10 was replacedby the composition (a) and that the solid electrolyte was formed byheating at 80° C. for 3 days, whereby a battery was fabricated.

COMPARATIVE EXAMPLE 2

The procedure for Example 4 was repeated except that the solidelectrolyte forming composition (I) employed in Example 4 was replacedby the composition (a) and that the solid electrolyte was formed byheating at 80° C. for 3 days, whereby a battery was fabricated.

The performance of each of the batteries fabricated in ComparativeExamples 1 and 2 was evaluated by conducting charging and discharging ofeach battery with a constant current of 0.5 mA. The results are shown inTABLE 11.

                  TABLE 11                                                        ______________________________________                                                   Open-      Discharge Discharge                                                circuit    Capacity  Capacity                                      Examples   Voltage    (initial) (after 30 cycles)                             ______________________________________                                        Comp. Ex. 1                                                                              3.7 V      2.0 mAh   0.5 mAh                                       Comp. Ex. 2                                                                              3.2 V      2.2 mAh   0.6 mAh                                       ______________________________________                                    

COMPARATIVE EXAMPLE 3

0.25 parts of methoxypolyethylene glycol monoacrylate (m.w. 496), 0.75parts of polyethylene glycol dimethacrylate (m.w. 550), 0.08 parts oflithium perchlorate, and 0.004 parts of2,2-dimethoxy-2-phenylacetophenone were mixed to prepare a uniformsolution. This liquid composition was thinly extended on a laboratorydish made of aluminum and irradiated with a super high pressure mercuryarc lamp in an atmosphere of nitrogen, whereby a solid electrolyte filmfree from solvents was obtained. The ionic conductivity of this film was3.7×10⁻⁷ S/cm*. A mixed solvent of propylene carbonate and 1,2-dimethoxyethane (6:4 by weight ratio) was contained in this film to prepare asolid electrolyte (the content of the electrolytic solution: 108%). Theionic conductivity of this solid electrolyte was 2.0×10⁻⁴ S/cm*. Theelectrolytic solution oozed from the surface of the solid electrolyte.When this solid electrolyte was held between two electrodes and pressurewas applied thereto in order to use the solid electrolyte as a solidelectrolyte for a battery, the solid electrode was broken and thebattery did not work.

A battery which contains the solid electrolyte of the present inventionhas a high ionic conductivity because the solid electrolyte is composedof a viscoelastic polymer containing a large amount of an electrolyticsolution, and the electrolytic solution does not leak. Furthermore,since the inside of the battery does not dry, and there is no imbalancedpresence of the electrolytic solution, and it does not occur that theseparator is partially dried, there is no increase in the internalimpedance. Therefore, in the present invention, no internal shortcircuits occur, so that highly reliable batteries and high voltage thinbatteries can be obtained. Therefore the present invention cansignificantly contribute to the reduction of the weight and size ofelectric appliances.

The solid electrolyte of the present invention can be used not only inbatteries, but also in condensers, capacitors, sensors and equipment foruse with organisms, such as electrodes for electrocardiography, contactsfor ultrasonography, and pads for fulguration, and electrochromicdevices, and can greatly contribute to the reduction of the weight andsize of such electric appliances.

What is claimed is:
 1. A solid electrolyte comprising a viscoelasticmaterial, wherein said viscoelastic material comprises a polymerizedmaterial and a non-aqueous electrolytic solution which is contained insaid polymerized material, said electrolytic solution being present inan amount of 200 wt. % or more of said polymerized material.
 2. A solidelectrolyte comprises a viscoelastic material, wherein said viscoelasticmaterial comprises a polymerized material and a non-aqueous electrolyticsolution which is contained in said polymerized material, the content ofsaid non-aqueous electrolytic solution being 200 wt. % or more of saidpolymerized material, said viscoelastic material having a modulus ofelasticity of 10² to 10⁵ dyne/cm², and an elongation of 20% or more. 3.The solid electrolyte as claimed in claim 1 or claim 2, wherein saidpolymerized material is a polymer of an unsaturated carboxylic acidester, a polymer of a mixture of polyene/polythiol, or a polyurethane.4. A solid electrolyte comprising a viscoelastic material, wherein saidviscoelastic material comprises a polymerized material of an acrylatehaving a molecular weight of 500 or less represented by formula (I), ora polymerized material of an unsaturated carboxylic acid estercomprising, as the main component, said acrylate of formula (I), and anon-aqueous electrolytic solution comprising an electrolytic salt and anon-aqueous solvent which is contained in said polymerized material, thecontent of said non-aqueous electrolytic solution being 200 wt. % ormore of said polymerized material, and said electrolytic salt beingpresent in a ratio of 1.0 mole/l or more in said non-aqueouselectrolytic solution: ##STR6## wherein R₁ represents a hydrogen atom,or a methyl group, R₂ represents a hydrocarbon group or a groupcontaining a heterocyclic ring, and n is an integer of 1 or more.
 5. Asolid electrolyte comprising a viscoelastic material, wherein saidviscoelastic material comprises a polymerized material of a compound offormula (II), or a polymerized material of an unsaturated carboxylicacid ester comprising, as the main component, said compound of formula(II), and a non-aqueous electrolytic solution comprising an electrolyticsalt and a non-aqueous solvent which is contained in said polymerizedmaterial, the content of said non-aqueous electrolytic solution being200 wt. % or more of said polymerized material, and said electrolyticsalt being present in a ratio of 1.0 mole/l or more in said non-aqueouselectrolytic solution: ##STR7## wherein R₃ represents a hydrogen atom,or a methyl group, and R₄ represents a group containing a heterocyclicring.
 6. The solid electrolyte as claimed in any of claims 1, 2, 4 or 5,wherein the content of said non-aqueous electrolytic solution is 400 to900 wt. %.
 7. The solid electrolyte as claimed in any of claims 1, 2, 4,or 5, wherein the concentration of said electrolytic salt is 2 to 5moles/l.
 8. The solid electrolyte as claimed in claim 4 or claim 5,wherein said unsaturated carboxylic acid ester comprises apolyfunctional unsaturated carboxylic acid ester having two or more(meth)acryloyl groups.
 9. The solid electrolyte as claimed in claim 8,wherein said polyfunctional unsaturated carboxylic acid ester is presentwith a ratio of 0.05 to 2 wt. % of said non-aqueous electrolyticsolution.
 10. An electrochemical device comprising a solid electrolyte,wherein said solid electrolyte is any of said solid electrolytes asclaimed in claims 1, 2, 4 or
 5. 11. The electrochemical device asclaimed in claim 10, wherein at least one part of the constituentelements of said electrochemical device and said solid electrolyte arecomposed.
 12. A battery comprising any of said solid electrolytes asclaimed in claim 1, 2, 4 or
 5. 13. A battery comprising electrodes, aseparator and a solid electrolyte, wherein said solid electrolyte is anyof said solid electrolytes as claimed in claim 1, 2, 4 or 5, whereinsaid electrode, said separator and said electrolyte are integrallycomposed.
 14. A method of fabricating a solid electrolyte comprising thestep of dissolving 100 parts of a compound of formula (I) or formula(II), or an unsaturated carboxylic acid ester comprising said compoundof formula (I) or formula (II) as the main component, in 200 or moreparts of a non-aqueous electrolytic solution having a concentration ofelectrolytic salt therein of 1.0 mole/l or more, in the presence of apolymerization initiator, and conducting a polymerization reaction toproduce a viscoelastic polymer: ##STR8## wherein R₁ represents ahydrogen atom, or a methyl group, R₂ represents a hydrocarbon group or agroup containing a heterocyclic ring, and n is an integer of 1 or more;and ##STR9## wherein R₃ represents a hydrogen atom, or a methyl group,and R₄ represents a group containing a heterocyclic ring.